Utility lines for gas, water, electricity and data are frequently buried underground. An increasing popular method of installing these lines is to drill a hole using a horizontal directional drilling technique. This technique allows the hole to pass under existing structures such as roads or sewers and existing geographical features such as rivers without disturbing them.
A typical horizontal directional drilling rig includes a frame on which is mounted a drive mechanism that can be slidably moved along the frame and which is adapted to rotate a drill string. Sliding the drive mechanism while rotating the drill string advances the drill string into the ground to create a hole. The drill string includes a drill head and a series of drill pipes. As the hole is lengthened, the drill string needs to be lengthened to permit the drill head to dig further through the ground. This is done by successively attaching drill pipes to the drill string as the drill is advanced into the ground. The hole is typically started at an oblique angle to the ground. When a desired depth is reached the drill head is directed to advance the hole in a substantially horizontal direction. Towards the end of the hole, the drill head is usually directed upwards at an angle until the drill string breaks through the surface. When the hole has been bored, this operation is reversed and drill pipes are successively removed from the drill string to shorten the drill string as it is retracted.
In a typical operation, the drill pipes are 32 feet long, have a 6 and ⅝ inch diameter and weigh approximately 1325 pounds. The drill pipes are hauled to the drilling site by truck and each pipe is individually lifted from the bed of the truck to attach it manually to the drill string. This operation is typically carried out by an excavator. A manual calipers, attached to the bucket of the excavator by a cable or nylon strap, is secured around a drill pipe. Balancing the drill pipe in the calipers, an operator uses the excavator to lift the drill pipe to the drill rig. Two or more workers steady and guide the drill pipe as it is moved into location by the excavator operator. At the drill rig, the workers manually tilt and rotate the pipe into position. In a typical operation, a drill pipe may be held horizontal or may be tilted about 12 degrees. A drill pipe is typically not tilted more than 35 degrees. Once the drill pipe is positioned as desired by the works and the excavator operator, the drill pipe is manually secured to the drill string. This is a cumbersome and dangerous operation which requires three or more workers (e.g., the one operating the excavator and at least two on the ground). There is thus a need for a device which improves safety and ease of use while reducing manpower.